Why not do the genesis quadrology with every playable character till Chaotix?

Just have them all playable across sonic 1, 2, 3&K and in Knuckles Chaotix and CD. Probably already hacks for it but that would be awesome if you just a choice of about ten characters all with different abilities.

The level design was balanced for three characters. Just wantonly throwing in a bunch of characters would definitely break the game; just look at what happens when you put the Spin Dash in Sonic 1 - you can barely even use it. The only game I could see this working for is Chaotix, but that's just because it doesn't even matter who you play as in that one since the game is more concerned with the elastic handcuff gimmick than anything else. Either way, we've played all of these games more times than we could count. I couldn't give less of a shit what they do to them anymore.